Field of the Invention
The present invention relates to an electrical connector for an implantable medical device.
Implantable medical devices include cardiac pacemakers, neurostimulators, cochlear implants, retinal prostheses, and many others. Frequently, there is a need to provide at least one electrical connection between various parts of an implantable medical device. For example, an implantable medical device for applying electrical stimulation could have an electrical connection between an implanted stimulator unit and a wire connected to an electrode element that applies stimulation to the desired region of tissue.
An electrical connection that is secure and reliable, ensures that the various components of the implantable medical device operate correctly, and that electrical current does not leak from the device and potentially cause damage to surrounding tissue.
In most implantable medical devices, the electrical connection is achieved via a permanent and rigid connection which cannot be readily disconnected and reconnected.
In the case of a cochlear implant, a stimulator unit embedded within the mastoid bone of the recipient, receives and directs stimulation signals to a plurality of electrodes that are inserted within the cochlea. Typically, the cochlear implant requires 22 to 24 electrical connections between the stimulator unit and the electrode array.
A hermetic feedthrough device normally provides the electrical connection between the wires connecting the electrodes to the stimulator unit. The wires connecting each of the electrodes are fixed to one side of the hermetic feedthrough device to form an electrical connection with the implant circuitry, which is connected to the other side of the feedthrough device. However, such an electrical connection does not allow for ready disconnection of the wires from the stimulator unit for later reconnection.
Hence, it has not been possible to replace the stimulator unit of a cochlear implant without replacing the entire cochlear implant. The electrode array is inserted within the cochlea, and removal requires the array to be removed from the position it has been in for some time, potentially years. This is problematic because of the risk of causing damage to the sensitive tissue structure.
The provision of a connector for an implantable device such as a cochlear implant Must be able to be used in a very confined space, since the components normally have dimensions in the order of nanometers or microns, up to the mm scale.
To further complicate the provision of such a connector system, the reconnection process must be able to take place in a fluid environment. This is desirable because a part of the system, for example the electrode array, can preferably remain permanently in position within the body.
It is desired to provide an implantable connector system capable of providing repeatable connections between a plurality of conductors of an implantable medical device.